Orphan nuclear receptor COUP-TFII is an oncogenic gene in renal cell carcinoma.

BACKGROUND: Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) may be an oncogenic gene in renal cell carcinoma (RCC). However, the direct association between COUP-TFII expression and patient survival has not been investigated in patients with RCC, and the molecular oncogenesis of COUP-TFII in RCC remains unclear. METHODS: The mRNA expression levels of COUP-TFII in the tumors of 283 patients with RCC were determined by RT-qPCR. The remaining 266 patients were categorized into low- and high-expression groups according to the cut off value generated by receiver operating curve (ROC) analysis. The function of COUP-TFII in RCC cells was tested by knockdown experiments in vitro. RESULTS: In the present study, it was revealed that the mRNA expression levels of COUP-TFII were significantly higher in tumors compared with those in adjacent non-cancerous tissues, and that the overexpression of COUP-TFII was strongly associated with poor patient survival. It was further demonstrated that knockdown of COUP-TFII suppressed proliferation, and induced apoptosis and cell cycle arrest in RCC cells in vitro. This also resulted in the activation of the mitochondria-mediated apoptosis pathway, impaired migration and invasion of RCC cells through epithelial-mesenchymal transition in vitro, and suppressed tumor growth in vivo. In addition, it was revealed that the induction of cell migration and invasion by COUP-TFII was mediated, at least in part, by integrin subunit ß1. CONCLUSIONS: In summary, the present study indicated that COUP-TFII is an oncogenic gene in RCC, and a potential therapeutic target for the treatment of the disease.

Influence of suppression of CapG gene expression by siRNA on the growth and metastasis of human prostate cancer cells.

This study investigated CapG gene expression in prostate cancer cell lines; in addition, we explored the effects of CapG suppression on DU145 cell growth, and the underlying mechanism with which CapG affects DU145 cell growth and invasiveness. The expression of CapG and 18 related genes in DU145 cells was analyzed by flow cytometry, quantitative polymerase chain reaction (qPCR), CCK8 assay, western blot, and the trans-well assay. DU145 cells were transfected with designed small interfering RNA (siRNA). CapG expression was quantified by qPCR and western blot. DU145 cell proliferation and invasiveness was analyzed using the CCK8, flow cytometric, and trans-well assays. CapG, TMPRSS1, EGFR, ETS-1, ERBB2, AKT, Cyclin D1, P21, Bcl-2, and Bak1 gene and Bcl-2, Cyclin D1, and CapG protein expressions were significantly lower in the siRNA group compared to the negative control group (P < 0.05). The proliferation of CapG siRNA DU145 cells was lower than that of the two control groups, 48 h after transfection. The cell inhibition rate was 24.5, 35.4, and 16,5% at 24, 48, and 72 h, respectively. The growth curve indicated that CapG siRNA DU145 cells showed a significantly slower proliferation rate (P < 0.05). The trans-well assay showed a significant decrease in the migratory and invasive capacities of DU145 cells in the siRNA group (P < 0.05). The suppression of CapG expression caused a significant decrease in the proliferation, invasiveness, and metastasis of DU145 cells. The mechanism with which CapG, with other oncogenes, influences cancer cell cycle remains to be elucidated.

Effect of p53 gene polymorphism on functions of prostate cancer cells.

Prostate cancer cells were transfected with plasmids [empty plasmids, wild-type pcDNA3.1-p53 (V/V), mutant type pcDNA3.1- p53 (G/G)] to analyze the effect of p53 gene polymorphisms on the proliferation, cycle, and apoptosis of prostatic cancer cells. Empty plasmids containing wild-type pcDNA3.1-p53 (V/V) and mutant type pcDNA3.1- p53 (G/G) were used to transfect PC3 and LNCaP cells, respectively. Cell proliferation was detected at 0, 24, 48, and 72 h using the MTT method. Cells were collected at 24 and 72 h. The distribution of cell cycles in various groups was detected using flow cytometry (propidium iodide staining method) and the apoptosis rate was detected using annexin V + propidium iodide double staining. Compared with the control group, wild-type pcDNA3.1-p53 (V/V) and mutant type pcDNA3.1-p53 (G/G) showed a significant inhibitory effect on cell proliferation (P < 0.05); the inhibitory effect of the mutant type was stronger than that of the wild-type. There was no significant difference between PC3 cells and LNCaP cells. After transfection with wild-type pcDNA3.1-p53 (V/V) and mutant type pcDNA3.1-p53 (G/G), PC3 and LNCaP cells were arrested in the G0/G1 stage. Transfection with pcDNA3.1-p53 (G/G) showed a more significant effect than transfection with pcDNA3.1-p53 (V/V). Both the wild-type pcDNA3.1-p53 (V/V) and mutant-type pcDNA3.1-p53 (G/G) led to an increased apoptosis rate of PC3 and LNCaP cells. The p53 gene polymorphism affects the proliferation, apoptosis, and cycle of prostate cancer cells and may serve as a reliable index for the diagnosis and treatment of prostate cancer.

Loss of STAG2 causes aneuploidy in normal human bladder cells.

The aim of this study was to determine how the function of human stromal antigen 2 (STAG2) plays an important role in proper chromosome separation. STAG2 mRNA in normal bladder cells and bladder tumor cells was evaluated by RT-PCR. The protein levels of STAG2 in normal bladder cells and bladder tumor cells were determined by western blot. A cell proliferation assay was used to measure the growth of tumor cells and STAG2-inhibited normal cells, and STAG2- inhibited normal cells were subjected to karyotype analysis. Both STAG-2 mRNA and protein expression levels were lower in bladder cancer cells compared to the controls. Knockdown of STAG2 caused aneuploidy in normal bladder cells, leading to a decreased expression of the cohesin complex components SMC1, SMC3 and RAD21, but there was no obvious effect of STAG2 knockdown on cell proliferation. Our study indicated that abnormal expression of STAG2 could cause aneuploidy in normal bladder cells.